Carpet calculator
Plan rectangular carpet strips cut in one direction.
Formula
Strips = ceil((width+trim)/roll width); roll length = strips × (length+trim)
Room length: 15 ft · Room width: 10 ft · Usable roll width: 12 ft · Total trim per dimension: 4 in · Full-length strips ≈ ceil((((10 ft × 0.3048 m/ft)+(4 in × 0.0254 m/in))÷(12 ft × 0.3048 m/ft))×(1-8.881784197001252e-16)) · Roll length to purchase ≈ (1)×((15 ft × 0.3048 m/ft)+(4 in × 0.0254 m/in)) · Purchased carpet area ≈ (4.6736)×(12 ft × 0.3048 m/ft)
How to use
- Enter the rectangular room and usable roll width.
- Enter total trimming allowance per dimension.
- Read roll length and purchased area.
Examples
- A 5 × 4.1 m room from a 4 m roll uses two 5 m strips.
Frequently asked questions
Why more than floor area?
You buy the full roll width even when the last strip is cut narrower.
Can I rotate the strips?
This model keeps one pile direction. Swap room dimensions only if the installation allows it.
Does it match patterns?
No. Pattern repeats, seams, stairs and offcut reuse need an installer’s layout.
Sources
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